export default {
  namespaced: true,
  state: () => ({
    //购物车数组,用来存储购物车中的每个商品的信息
    //每个商品的信息对象，
    //{goods_is,goods_name,goods_price,goods_count,goods_small_logo,goods_state}
    cart: JSON.parse(uni.getStorageSync('cart') || '[]')
  }),
  mutations: {
    addToCart(state, goods) {
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      //如果undefined
      if (!findResult) {
        state.cart.push(goods)
      } else {
        findResult.goods_count++
      }

      //通过commit调用m_cart 下的方法完成持久化
      this.commit('m_cart/saveToStorage')
    },
    //持久化存储
    saveToStorage(state) {
      uni.setStorageSync('cart', JSON.stringify(state.cart))
    },
    //更新购物车商品的勾选状态
    updateGoodsState(state, goods) {
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)

      if (findResult) {
        findResult.goods_state = goods.goods_state
        //持久化
        this.commit('m_cart/saveToStorage')
      }
    },
    updateGoodsCount(state, goods) {
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)

      if (findResult) {
        findResult.goods_count = goods.goods_count
        //持久化
        this.commit('m_cart/saveToStorage')
      }
    },
    //根据Id删除对应的商品
    removeGoodsById(state, goods_id) {
      state.cart = state.cart.filter(x => x.goods_id !== goods_id)
      //持久化
      this.commit('m_cart/saveToStorage')
    },
    //更新所有商品的勾选状态
    updateAllGoodsState(state, newState) {
      state.cart.forEach(x => x.goods_state = newState)
      //持久化
      this.commit('m_cart/saveToStorage')
    }
  },

  getters: {
    //购物车中所有商品的总数量
    total(state) {
      // let c = 0
      // //计算购物车总数量
      // state.cart.forEach(goods => c += goods.goods_count)
      // return c
      return state.cart.reduce((total, item) => total += item.goods_count, 0)
    },
    //已勾选的数量
    checkedCount(state) {
      return state.cart.filter(x => x.goods_state).reduce((total, item) => total += item.goods_count, 0)
    },
    checkedGoodsAmount(state) {
      return state.cart.filter(x => x.goods_state).reduce((total, item) => total += item.goods_count * item.goods_price,
        0).toFixed(2)
    }
  }
}